The effects of cooperation between orthopaedic surgeons and microbiologists on the effectiveness of diagnosis and treatment of septic hip joint loosening.

Background: The objective of this study is to compare the results of microbiological examinations of two types of materials: specimens collected intraoperationally upon removal of prostheses following septic loosening and cultures from sonicated implants. The study was the effect of collaboration between the Clinic of Orthopedics of A. Gruca Hospital in Otwock and the Department of Microbiology in Lublin.

Material And Methods: The study population consisted of 24 patients aged 39 to 84 years, average of 68 years, undergoing surgeries at the Department of Bone and Joint Inflammation, Clinic of Orthopedics of A. Gruca Hospital in Otwock in years 2010-2011. All patients were qualified for surgical treatment consisting of removal of hip prosthesis due to inflammation. Sixty percent of the group were women, while the remaining forty percent were men. The methodology of the study was based on intraoperational collection of material for microbiological examinations at the Department of Microbiology of A. Gruca Hospital. The study material was collected from 3 locations: femoral shank, hip acetabulum and gluteal muscle. Explanted implants were placed in sterile containers, frozen at -20°C and transported to the Department of Microbiology in Lublin. There, the implants were sonicated.

Results: The obtained results were consistent in both groups in 37% of cases. In 9 patients (37%), standard cultures were negative while the cultures of sonicated material were positive. In 16 patients (67%), the spectrum of perioperative and sequential antibiotic therapy included flora cultured by standard methods as well as flora obtained from sonicated implant cultures. In the remaining patients, cultures obtained from sonicated material were resistant to antibiotics used.

Conclusions: Cultures of sonicated implant materials increase the chance for identification of microbes responsible for inflammation. Limitations of the method include the requirement to either examine the implant shortly after removal or freeze the implant in order to prevent secondary infections of the material.